Integrated showerhead with thermal control for delivering radical and precursor gas to a downstream chamber to enable remote plasma film deposition

ABSTRACT

A substrate processing system includes a first chamber including a substrate support. A showerhead is arranged above the first chamber and is configured to filter ions and deliver radicals from a plasma source to the first chamber. The showerhead includes a heat transfer fluid plenum, a secondary gas plenum including an inlet to receive secondary gas and a plurality of secondary gas injectors to inject the secondary gas into the first chamber, and a plurality of through holes passing through the showerhead. The through holes are not in fluid communication with the heat transfer fluid plenum or the secondary gas plenum.

INCORPORATION BY REFERENCE

An Application Data Sheet is filed concurrently with this specification as part of the present application. Each application that the present application claims benefit of or priority to as identified in the concurrently filed Application Data Sheet is incorporated by reference herein in their entireties and for all purposes.

FIELD

The present disclosure relates to substrate processing systems, and more particularly to substrate processing systems including showerheads that deliver radicals and precursor gas to a downstream chamber.

BACKGROUND

The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

Substrate processing systems may be used to deposit film on a substrate such as a semiconductor wafer. The substrate processing systems typically include a processing chamber and a substrate support. During film deposition, radicals and precursor gas maybe supplied to the processing chamber.

For example, the processing chamber may include an upper chamber, a lower chamber and a substrate support. A showerhead may be arranged between the upper chamber and the lower chamber. The substrate is arranged on the substrate support in the lower chamber. A plasma gas mixture is supplied to the upper chamber and plasma is struck in the upper chamber. Some of the radicals generated by the plasma flow through the showerhead to the lower chamber. The showerhead filters ions and shields UV light from reaching the lower chamber. A precursor gas mixture is supplied to the lower chamber through the showerhead and reacts with the radicals to deposit film on the substrate.

Typically, the showerhead does not have a thermal control system. However, in some processing systems, a basic thermal control system is used to control a temperature of an outer edge of the showerhead, which is accessible and not under vacuum. The basic thermal control system does not uniformly control temperature across the showerhead due to the heat from the plasma. In other words, the temperature at the center of the showerhead increases. Temperature changes also occur with process changes such as plasma on/off, pressure, flow rate, and/or pedestal temperature. Variations in the temperature of the showerhead adversely impact the uniformity of the deposition process and defect performance.

SUMMARY

A substrate processing system includes a first chamber including a substrate support. A showerhead is arranged above the first chamber and is configured to filter ions and deliver radicals from a plasma source to the first chamber. The showerhead includes a heat transfer fluid plenum including an inlet to receive heat transfer fluid and a plurality of flow channels to direct the heat transfer fluid through a center portion of the showerhead to an outlet to control a temperature of the showerhead, a secondary gas plenum including an inlet to receive secondary gas and a plurality of secondary gas injectors to inject the secondary gas into the first chamber, and a plurality of through holes passing through the showerhead. The through holes are not in fluid communication with the heat transfer fluid plenum or the secondary gas plenum.

In other features, the heat transfer fluid plenum includes a first plenum in fluid communication with the inlet. The first ends of the flow channels are in communication with the first plenum. A second plenum is in fluid communication with opposite ends of the flow channels.

In other features, the heat transfer fluid plenum includes a first plenum in fluid communication with the inlet, a second plenum in fluid communication with first ends of the flow channels, a first plurality of restrictions arranged between the first plenum and the second plenum to restrict fluid flow therebetween, a third plenum in fluid communication with opposite ends of the flow channels, a fourth plenum in fluid communication with the outlet, and a second plurality of restrictions arranged between the third plenum and the fourth plenum to restrict fluid flow therebetween.

In other features, the plurality of flow channels flow in a radial direction from one side of the showerhead to an opposite side of the showerhead. The plurality of flow channels defines a straight path. The plurality of flow channels defines a curved path. The plurality of flow channels defines a sinusoidal-shaped path.

In other features, the secondary gas plenum includes a first plenum, a second plenum, and a flow restriction arranged between the first plenum and the second plenum.

In other features, the flow restriction comprises a first plurality of walls, and a plurality of slots defined between the first plurality of walls. The first plurality of walls is arcuate-shaped. A second plurality of walls is arranged around the through holes in the second plenum. The second plurality of walls is cylinder-shaped.

In other features, the secondary gas injectors are in fluid communication with the second plenum. A plurality of restrictions arranged between the second plenum and the secondary gas injectors.

In other features, the plurality of flow channels includes inlets and outlets. The inlets of the plurality of flow channels are arranged on one side of the showerhead, the outlets of the plurality of flow channels are arranged on the one side between the inlets, and the plurality of flow channels connect to the inlets, travel across the showerhead and return back across the showerhead to the outlets.

In other features, a second chamber is arranged above the first chamber. The showerhead is arranged between the first chamber and the second chamber. A coil is arranged around the second chamber. An RF generator is connected to the coil to generate plasma in the second chamber.

In other features, at least one of the flow channels includes a flow restriction. The heat transfer fluid comprises liquid. The heat transfer fluid comprises gas. The heat transfer fluid does not flow into the first chamber.

In other features, the secondary gas injectors extend a predetermined distance from a bottom surface of the showerhead, wherein the predetermined distance is in a range from 0.1″ to 1.5″. The through holes have a diameter in a range from 0.05″ to 0.3″.

In other features, the showerhead includes a cylindrical wall that extends from a bottom surface thereof and that is located radially outside of the plurality of through holes and the plurality of secondary gas injectors. The showerhead includes a cylindrical wall that extends upwardly from a top surface thereof and that is located radially outside of the plurality of through holes and the plurality of secondary gas injectors.

In other features, a first O-ring is arranged between a top surface of the showerhead and the upper chamber and a second O-ring is arranged between the bottom surface of the showerhead and the lower chamber.

Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

FIG. 1 is a functional block diagram of an example of a substrate processing chamber including a showerhead according to the present disclosure;

FIG. 2A is a bottom perspective view of an example of the showerhead according to the present disclosure;

FIG. 2B is a side cross-sectional view illustrating a groove for receiving an O-ring according to the present disclosure;

FIG. 3 is a top perspective view of an example of the showerhead according to the present disclosure;

FIG. 4A is a plan view illustrating a bottom surface of an example of the showerhead according to the present disclosure;

FIG. 4B is a plan view illustrating an example of a plurality of through holes arranged around a secondary gas injector according to the present disclosure;

FIG. 4C is a plan view illustrating another example of a plurality of through holes arranged around a secondary gas injector according to the present disclosure;

FIG. 5A is a side cross-sectional view of an example of the showerhead according to the present disclosure;

FIG. 5B is a side cross-sectional view of an example showing a showerhead formed by multiple adjacent layers;

FIG. 6 is an enlarged side cross-sectional view of another example of the showerhead according to the present disclosure;

FIG. 7 is a side cross-sectional view of the showerhead of FIG. 6 according to the present disclosure;

FIG. 8A is an enlarged side cross-sectional view of another example of the showerhead including a downwardly-projecting wall according to the present disclosure;

FIG. 8B is an enlarged side cross-sectional view of another example of the showerhead including an upwardly-projecting wall according to the present disclosure;

FIG. 9 is a plan view of an example of a top surface of a middle layer of the showerhead according to the present disclosure;

FIG. 10 illustrates an example of a channel with a restriction to control flow of fluid through the channel according to the present disclosure;

FIG. 11 is a plan view of an example of a bottom surface of the middle layer of the showerhead according to the present disclosure;

FIG. 12 is a plan view of another example of a top surface of the middle layer of the showerhead including alternating heat transfer fluid inlet and outlet pairs arranged along one edge thereof according to the present disclosure;

FIG. 13 is a plan view of a bottom surface of the middle layer of the showerhead in FIG. 12 according to the present disclosure; and

FIG. 14 is a side cross-sectional view of the showerhead in FIGS. 12 and 13 .

In the drawings, reference numbers may be reused to identify similar and/or identical elements.

DETAILED DESCRIPTION

The present disclosure relates to a substrate processing system including an integrated, flush-mount showerhead that delivers uniform radicals and filters ions from a remote plasma source. The showerhead provides uniform temperature control by supplying heat transfer fluid to channels through a center portion of the showerhead to maintain a uniform and controlled temperature. The showerhead also supplies uniform precursor gas flow delivery to a chamber including the substrate. In some examples, the substrate processing system can be used to deposit conformal carbide films, although other types of film can be deposited.

Referring now to FIG. 1 , a substrate processing system 10 includes an upper chamber 20 and a lower chamber 30. While a specific type of substrate processing system is shown and described, other types may be used. While inductively coupled plasma is shown, other types of plasma generation may be used such as capacitively coupled plasma, remote plasma sources, or other suitable plasma generators.

In some examples, the upper chamber 20 may include a dome shaped chamber, although other chamber shapes can be used. A substrate support 34 is arranged in the lower chamber 30. A substrate 36 is arranged on the substrate support 34 during substrate treatment. A showerhead 40 is arranged between the upper chamber 20 and the lower chamber 30. Inductive coils 42 may be arranged around the upper chamber 20.

A gas delivery system 50-1 may be used to supply a process gas mixture including plasma gas to the upper chamber 20. The gas delivery system 50-1 includes one or more gas sources 52-1, 52-2, . . . , and 52-N, valves 54-1, . . . , and 54-N, mass flow controllers (MFC) 56-1, . . . , and 56-N, and a manifold 58, although other types of gas delivery systems can be used (where N is an integer). A gas delivery system 50-2 delivers a process gas mixture including precursor gas to the showerhead 40.

An RF plasma generator 66 includes an RF source 70 and a matching network 72. The RF plasma generator 66 selectively supplies RF power to the inductive coil 42 (while plasma gas is supplied) to generate plasma 62 in the upper chamber 20.

A thermal control system 86 may be used to supply heat transfer fluid such as gas or a liquid coolant to the showerhead 40 to control a temperature of the showerhead 40. A valve 88 and a pump 90 may be used to evacuate reactants.

A controller 94 communicates with the gas delivery systems 50-1 and 50-2 to selectively supply process gases as needed to the upper chamber 20 and the showerhead 40. The controller 94 communicates with the RF plasma generator 66 to generate and extinguish plasma in the upper chamber 20.

The controller 94 communicates with the thermal control system 86 to control a flow rate and temperature of heat transfer fluid that is used to control the temperature of the showerhead 40. In some examples, the heat transfer fluid may include water, water mixed with ethylene glycol, perfluoropolyether fluorinated fluid or other fluid and/or one or more gases. In some examples, the thermal control system 86 controls the flow rate or temperature of the heat transfer fluid using closed loop control. In other examples, the thermal control system 86 controls the flow rate and temperature using proportional integral derivative (PID) control. The heat transfer fluid may be provided in an open loop system from a building water circulation system. In some examples, the heat transfer fluid is hermetically sealed from the vacuum chamber.

In some examples, the controller 94 may be connected to one or more temperature sensors (not shown) arranged in the showerhead 40 to sense one or more temperatures of the showerhead 40. In some examples, the controller 94 may be connected to one or more pressure sensors (not shown) arranged in the showerhead 40 to sense one or more pressures in the processing chamber. The controller 94 communicates with the valve 88 and the pump 90 to control pressure within the upper and lower chambers 20, 30 and to selectively evacuate reactants therefrom.

Referring now to FIGS. 2A-3 , a top surface 102, a bottom surface 104 and a side surface 108 of the showerhead 40 are shown. In FIG. 2A, the showerhead 40 includes a plurality of spaced through holes 110 that pass from the top surface 102 of the showerhead 40 to the bottom surface 104 of the showerhead 40 in an axially central portion or center of the showerhead. In some examples, an O-ring 111 may be located between the bottom surface 104 of the showerhead 40 and the lower chamber 30 as shown in FIG. 2B. A groove 113 may be located on one or both of the showerhead 40 and the lower chamber 30 to position the O-ring 111.

A plurality of secondary gas injectors 112 supply secondary gas such as precursor gas from the showerhead 40. In some examples, the secondary gas injectors 112 extend downwardly from the bottom surface 104 of the showerhead 40 in the center portion of the showerhead 40. In some examples, the secondary gas injectors 112 include a restriction (not shown) on the bottom surface 104 to prevent back-diffusion and to make gas flow uniform from one secondary gas injector to another. The restriction may induce choked flow conditions.

In FIG. 3 , the showerhead 40 includes pairs of thermal fluid ports 120, 122 to act as an inlet and outlet. The showerhead 40 may contain more than one thermal fluid plenum with more pairs of ports. A leak collection tray 128 may be arranged around one or both of the thermal fluid ports 120, 122. The leak collection tray 128 may be arranged outside of the upper and lower chambers. The leak collection tray 128 allows leak detection. In some examples, an O-ring 115 may be located between the top surface 102 of the showerhead 40 and the upper chamber 20.

A groove may be located on one or both of the showerhead 40 and the upper chamber 20 to position the O-ring 111 in a manner similar to that shown in FIG. 2B.

Referring now to FIG. 4A, the through holes 110 and the secondary gas injectors 112 of the showerhead 40 may be arranged in various patterns. For example, the through holes 110 and the secondary gas injectors 112 of the showerhead 40 shown in FIG. 4A may have an offset triangular pattern T. Alternate patterns include rectangular, radial, hexagonal or spiral patterns, although other patterns can be used. In some examples, spacing of the secondary gas injectors 112 is in a range from 0.25″ to 2″. In some examples, the through holes 110 may have the same spacing as the secondary gas injectors, although different spacing may be used as shown in FIGS. 4B and 4C.

In some examples, the through holes 110 may include a plurality of smaller through holes that are clustered around each secondary gas injector 112 as shown in the examples in FIG. 4B and 4C. The arrangement of the through holes 110 around the secondary gas injectors 112 can be uniform as shown in FIG. 4B or non-uniform as shown in FIG. 4C. In some examples, a through hole 110-R is located on a radial line of the showerhead 40 on a side of the secondary gas injector closes to a center of the showerhead 40.

Referring now to FIGS. 5A-8B, side cross-sectional views of the showerhead 40 are shown. In FIG. 5A, the through holes 110 pass from the top surface 102of the showerhead 40 to the bottom surface 104 thereof. One or more heat transfer fluid plenums 140 are located in one or more planes that are perpendicular to the through holes 110 and parallel but offset from the top surface 102 of the showerhead 40. One or more secondary gas plenums 150 are located in one or more planes that are perpendicular to the through holes 110 and parallel but offset from the bottom surface 104 of the showerhead 40 and the one or more planes including the heat transfer fluid plenums 140. The configuration shown is the heat transfer fluid plenum above the secondary gas plenum. The plenums may be reversed so that the secondary gas plenum is above the heat transfer fluid plenum.

The one or more heat transfer fluid plenums 140 are connected to thermal fluid ports 120, 122. The one or more secondary gas plenums 150 receive gas from the secondary gas inlet (FIG. 2A) and supply the secondary gas flow to flow channels 152 of the secondary gas injectors 112.

In some examples, the secondary gas injectors 112 extend a predetermined distance away from a bottom surface of the showerhead 40 to reduce deposition of film on the showerhead 40. In some examples, the predetermined distance is in a range from 0.1″ to 1.5″, although other distances can be used. In some examples, the secondary gas injectors 112 include a restriction to prevent back diffusion and ensure flow uniformity from one secondary gas injector to another. In some examples, the through holes 110 have a diameter in a range from 0.05″ to 0.3″.

In FIG. 5B, the showerhead 40 can be made of multiple layers including a top layer 163, a middle layer 165 and a bottom layer 167 that are connected together. More layers may be added to create additional plenums. In some examples, the showerhead 40 can be manufactured using vacuum brazing, tungsten inert gas (TIG) welding, or electron beam welding to enable complex and unique geometries at a reasonable cost. Vacuum braze joining allows the showerhead to be machined as flat plates with grooves cut into the plates with a layer of braze between each plate. Welding techniques require more complex sub-components for the weld to access all areas which require sealing. Posts and corresponding holes may be machined to raise the sealing area to the surface of the part where it is accessible to weld.

In some examples, a top surface of the middle layer 165 defines the one or more heat transfer fluid plenums 140 and a bottom surface of the middle layer 165 defines the one or more secondary gas plenums 150. However, a bottom surface of the top layer 163 can be used to partially or fully define the one or more heat transfer fluid plenums 140 and the top surface of the bottom layer 167 can be used to fully or partially define the one or more secondary gas plenums.

In some examples, the thickness of the plenums and material above and below them is 0.05″ to 0.25″, although other thicknesses can be used. The thickness of the material in-between and above/below the plenums is determined by the strength needed to support the fluid pressure and material thickness required for manufacturing. A thickness of the heat transfer fluid plenum 140 may be sized to reduce a pressure drop of the fluid. A size of the secondary gas plenum 150 may be selected large enough to allow uniform distribution of gas to each injector 112. The thickness of each layer should be minimized to reduce the overall thickness to reduce loss of radicals in the through holes 110.

In some examples, the thickness of the top layer 163 and the bottom layer 167 is in a range from 0.075″ to 0.125″, although other thicknesses can be used. In some examples, the thickness of the top layer 163 and the bottom layer 167 is 0.1″, although other thicknesses can be used. In some examples, the thickness of the middle layer 165 is in a range from 0.4″ to 0.6″, although other thicknesses can be used. In some examples, the thickness of the middle layer 165 is 0.5″, although other thicknesses can be used. In some examples, the thickness of the showerhead is less than or equal to 1″. In some examples, the thickness of the showerhead is less than or equal to 0.7″.

In FIGS. 6 and 7 , the leak collection tray 128 is shown. The leak collection tray 128 includes a recess that is arranged around at least one of the thermal fluid ports 120, 122. In some examples, the recess is cylinder-shaped, although other shapes can be used.

In FIG. 8A, some examples include a cylindrical wall 210 that extends downwardly (near or spaced radially inwardly) from a radially outer edge 208 of the showerhead 40 towards the substrate 36 (and radially outside of the through holes 110 and the secondary gas injectors 112). The cylindrical wall 210 may be integrated with or attached to the showerhead 40. The cylindrical wall 210 improves thermal uniformity between the showerhead 40 and the chamber wall seen by the substrate. The cylindrical wall 210 may also be used to control exhaust port pumping non-uniformity by creating a flow restriction between the wall and the substrate support 34. In some examples, the cylindrical wall 210 extends below a plane including a top surface of the substrate support 34.

In FIG. 8B, some examples include a cylindrical wall 211 that extends upwardly (near or spaced radially inwardly) from a radially outer edge 208 of the showerhead 40 (and radially outside of the through holes 110 and the secondary gas injectors 112). The cylindrical wall 211 may be integrated with or attached to the top surface of showerhead 40. The cylindrical wall 211 provides a mounting surface for mounting a radical source.

Referring now to FIG. 9-10 , an example arrangement of the one or more heat transfer fluid plenums 140. In FIG. 9 , the top surface of the middle layer 165 is shown. The one or more heat transfer fluid plenums 140 include a first plenum 156-1. In some examples, the first plenum 156-1 has an arcuate shape, although other shapes can be used. In some examples, a plurality of restrictions 158-1 is arranged adjacent to one another on one side of the first plenum 156-1. Spacing between each of the plurality of restrictions 158-1 is selected to restrict and distribute flow from the first plenum 156-1 into a second plenum 156-2. In some examples, each the plurality of restrictions 158-1 includes a post having a round, elliptical or oblong shape, although other shapes can be used. The plurality of restrictions 158-1 may be used to make fluid flow between the flow channels 160 more uniform and to eliminate jetting effects. Alternately, one or more of the flow channels 160 can include a restriction 164 to control flow as shown in FIG. 10 . If the flow channels 160 include the restriction 164, the plurality of restrictions 158-1 can be omitted and the first and second plenums 156-1 and 156-2 can be a single plenum.

The second plenum 156-2 opens into first ends of flow channels 160. In some examples, the flow channels 160 have a triangular, square-wave, curved or generally sinusoidal shape to increase surface area. Second ends of the flow channels 160 are connected to a third plenum 156-3 arranged at an opposite side of the showerhead 40. A plurality of restrictions 158-2 is arranged on one side of the third plenum 156-3. Each of the plurality of restrictions 158-2 is arranged to restrict flow into a fourth plenum 156-4. The fourth plenum 156-4 is connected to an outlet. If the flow channels 160 include the restriction 164, the plurality of restrictions 158-2 can be omitted and the third and fourth plenums 156-3 and 156-4 can be a single plenum.

In some examples, the thermal fluid flow channels 160 have a channel to channel non-uniformity of less than or equal to 10% flow rate. In some examples, the thermal fluid flow rate is 10 gallons per minute and controls the entire showerhead surface to +−1 degree Celsius. In some examples, the secondary gas injectors 112 have flow non-uniformity less than or equal to 1% mass flow rate. In some examples, the secondary gas injectors 112 have non-uniformity less than or equal to 0.1% mass flow rate.

In FIG. 11 , the bottom surface of the middle layer 165 is shown. The one or more secondary gas plenums 150 include a gas inlet 172 and a flow passage 174 in fluid communication with a first plenum 176-1 and a second plenum 176-2. A first plurality of walls 180 are arranged between the first plenum 176-1 and the second plenum 176-2. A plurality of slots 184 is arranged between ends of the plurality of walls 180 to restrict flow between the first plenum 176-1 and the second plenum 176-2. In some examples, the first plenum 176-1 is ring-shaped, the second plenum 176-2 is circular and the first plurality of walls 180 is arcuate-shaped, although other shapes can be used.

A second plurality of walls 190 is arranged around the through holes 110. In some examples, the second plurality of walls 190 has a cylindrical shape, although other shapes can be used. In some examples, a top edge of the second plurality of walls 190 provides a bonding area to create a vacuum seal between the second plenum 176-2 and the through holes 110. In some examples, a plurality of restrictions 186 is provided at inlets of the secondary gas injectors 112 to control flow of the secondary gas from the second plenum 176-2 to the lower chamber 30.

In some examples, the slots 184 are sized relative to the restrictions 186 such that the pressure drop ΔP_(slots) at the slots 184 is significantly greater than the pressure drop ΔP_(first plenum). In some examples, ΔP_(slots) is 20 times greater than ΔP _(first plenum). In some examples, ΔP_(slots) is 5 times greater than ΔP_(first plenum).

Referring now to FIGS. 12-14 , a middle portion 300 of another showerhead 40 is shown to include heat transfer fluid inlets and outlets arranged along one side thereof. In other words, the flow channels travel from the inlets across the showerhead and return back across the showerhead to the outlets.

In FIG. 12 , a top side of the middle portion 300 is shown. A fluid inlet 310 is connected to fluid inlet plenum 320. In some examples, the fluid inlet plenum 320 is arcuate-shaped. Inlets 324 to a plurality of flow channels 330 are connected to the fluid inlet plenum 320. The plurality of flow channels 330 traverse across the showerhead 40, turn and return back to outlets 334 that are located between adjacent ones of the inlets 324. While the flow channels 330 are shown as straight segments, non-straight flow channels such as those shown above can be used to increase surface area and heat transfer (or a combination of straight and curved can be used).

The outlets 334 pass through gas vias 338 in the middle portion 300 to an outlet plenum 350 located on a bottom side of the middle portion 300 in FIG. 13 . The outlet plenum 350 is connected to a fluid outlet 358. As can be appreciated, the bottom surface of the middle portion 300 may also include a secondary gas plenum similar to that shown above in FIG. 11 . The size of the vias 338 may be varied to compensate for non-uniform flow rate from channel to channel to achieve the same uniformity as using restrictions 158-1 or restrictions 158-2.

The integrated showerheads described herein deliver sufficient and uniform radicals, filter ions from a remote plasma source, provide uniform temperature control, and supply uniform precursor. In some examples, thermal control provided by the showerheads including the heat transfer fluid channels described above control thermal non-uniformity across the substrate to less than 5° C. The heat transfer fluid channels are also capable of controlling the heat generated from the plasma contained in the volume of the upper chamber 20. The showerhead further includes an internal secondary gas plenum that provides uniform precursor delivery to the lower chamber. In some examples, gas outlets from the secondary gas plenum are offset by a predetermined distance from a bottom surface of the showerhead to minimize deposition on the showerhead and extend time between cleans.

The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Further, although each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of the disclosure can be implemented in and/or combined with features of any of the other embodiments, even if that combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments with one another remain within the scope of this disclosure.

Spatial and functional relationships between elements (for example, between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including “connected,” “engaged,” “coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and “disposed.” Unless explicitly described as being “direct,” when a relationship between first and second elements is described in the above disclosure, that relationship can be a direct relationship where no other intervening elements are present between the first and second elements, but can also be an indirect relationship where one or more intervening elements are present (either spatially or functionally) between the first and second elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”

In some implementations, a controller is part of a system, which may be part of the above-described examples. Such systems can comprise semiconductor processing equipment, including a processing tool or tools, chamber or chambers, a platform or platforms for processing, and/or specific processing components (a substrate pedestal, a gas flow system, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after processing of a semiconductor substrate or substrate. The electronics may be referred to as the “controller,” which may control various components or subparts of the system or systems. The controller, depending on the processing requirements and/or the type of system, may be programmed to control any of the processes disclosed herein, including the delivery of processing gases, temperature settings (e.g., heating and/or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, positional and operation settings, substrate transfers into and out of a tool and other transfer tools and/or load locks connected to or interfaced with a specific system.

Broadly speaking, the controller may be defined as electronics having various integrated circuits, logic, memory, and/or software that receive instructions, issue instructions, control operation, enable cleaning operations, enable endpoint measurements, and the like. The integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and/or one or more microprocessors, or microcontrollers that execute program instructions (e.g., software). Program instructions may be instructions communicated to the controller in the form of various individual settings (or program files), defining operational parameters for carrying out a particular process on or for a semiconductor substrate or to a system. The operational parameters may, in some embodiments, be part of a recipe defined by process engineers to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and/or dies of a substrate.

The controller, in some implementations, may be a part of or coupled to a computer that is integrated with the system, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller may be in the “cloud” or all or a part of a fab host computer system, which can allow for remote access of the substrate processing. The computer may enable remote access to the system to monitor current progress of fabrication operations, examine a history of past fabrication operations, examine trends or performance metrics from a plurality of fabrication operations, to change parameters of current processing, to set processing steps to follow a current processing, or to start a new process. In some examples, a remote computer (e.g. a server) can provide process recipes to a system over a network, which may include a local network or the Internet. The remote computer may include a user interface that enables entry or programming of parameters and/or settings, which are then communicated to the system from the remote computer. In some examples, the controller receives instructions in the form of data, which specify parameters for each of the processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process to be performed and the type of tool that the controller is configured to interface with or control. Thus as described above, the controller may be distributed, such as by comprising one or more discrete controllers that are networked together and working towards a common purpose, such as the processes and controls described herein. An example of a distributed controller for such purposes would be one or more integrated circuits on a chamber in communication with one or more integrated circuits located remotely (such as at the platform level or as part of a remote computer) that combine to control a process on the chamber.

Without limitation, example systems may include a plasma etch chamber or module, a deposition chamber or module, a spin-rinse chamber or module, a metal plating chamber or module, a clean chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing systems that may be associated or used in the fabrication and/or manufacturing of semiconductor substrates.

As noted above, depending on the process step or steps to be performed by the tool, the controller might communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout a factory, a main computer, another controller, or tools used in material transport that bring containers of substrates to and from tool locations and/or load ports in a semiconductor manufacturing factory. 

What is claimed is:
 1. An apparatus for use in processing substrates, the apparatus comprising: a showerhead formed by a plurality of layers that are bonded together to form a contiguous structure, wherein: the showerhead includes a plurality of through-holes extending from a top surface of the showerhead to a bottom surface of the showerhead opposite the top surface, the showerhead includes a secondary gas plenum located in between the top surface of the showerhead and the bottom surface of the showerhead, a plurality of secondary gas injection ports lead from the secondary gas plenum to the bottom surface of the showerhead, and a cylindrical wall encircles the through-holes and the plurality of secondary gas injection ports and extends from the bottom surface of the showerhead by a first distance.
 2. The apparatus of claim 1, wherein the cylindrical wall and the plurality of layers form a contiguous structure.
 3. The apparatus of claim 1, wherein the secondary gas injection ports protrude outward from the bottom surface of the showerhead by a second distance that is less than the first distance.
 4. The apparatus of claim 1, wherein the cylindrical wall is offset radially inward from an outer edge of the showerhead.
 5. The apparatus of claim 1, wherein a portion of the showerhead that is radially outward of the cylindrical wall is thicker than a portion of the showerhead that is radially inward of the cylindrical wall.
 6. The apparatus of claim 1, wherein: the showerhead further includes a heat transfer fluid plenum that is also interposed between the top surface of the showerhead and the bottom surface of the showerhead, and the heat transfer fluid plenum has a plurality of walls, each wall encircling one of the through-holes and sealing the through-hole from the heat transfer plenum.
 7. The apparatus of claim 6, wherein: the showerhead further includes a heat transfer fluid inlet and a heat transfer fluid outlet, and the heat transfer fluid inlet and the heat transfer fluid outlet are both connected with the heat transfer fluid plenum.
 8. The apparatus of claim 6, wherein the plurality of layers includes a top layer, a middle layer, and a bottom layer.
 9. The apparatus of claim 8, wherein a bottom surface of the top layer partially or fully defines the heat transfer fluid plenum.
 10. The apparatus of claim 9, wherein a top surface of the bottom layer partially or fully defines the secondary gas plenum.
 11. The apparatus of claim 8, wherein a top surface of the bottom layer partially or fully defines the secondary gas plenum.
 12. The apparatus of claim 6, wherein: the heat transfer fluid plenum includes a first arcuate plenum and a second arcuate plenum, a plurality of flow channels extend between the first arcuate plenum and the second arcuate plenum, and the flow channels are arranged side-by-side and extend along parallel directions.
 13. The apparatus of claim 12, wherein each flow channel follows a sinusoidal or square-wave path.
 14. The apparatus of claim 12, further comprising: a first plurality of posts distributed along a first arcuate path within the first arcuate plenum, and a second plurality of posts distributed along a second arcuate path within the second arcuate plenum.
 15. The apparatus of claim 6, wherein: the heat transfer fluid plenum includes a fluid inlet plenum and a plurality of flow channels, the flow channels each follow a corresponding path that leads from a first end that connects with the fluid inlet plenum to a second end that terminates at a corresponding via, at least some of the paths extend along a first direction across the showerhead before reversing to extend along a second direction opposite the first direction, and the vias connect with a fluid outlet plenum located at a different elevation than the fluid inlet plenum.
 16. The apparatus of claim 15, wherein the fluid inlet plenum and the fluid outlet plenum are both arcuate in shape.
 17. The apparatus of claim 15, wherein at least some of the vias have different cross-sectional areas.
 18. The apparatus of claim 16, wherein at least some of the paths are sinusoidal or square-wave.
 19. The apparatus of claim 16, wherein the fluid inlet plenum and the fluid outlet plenum are aligned with each other when viewed along a direction perpendicular to the bottom surface of the showerhead.
 20. The apparatus of claim 1, further comprising: a processing chamber; and a substrate support, wherein the showerhead is positioned above the substrate support.
 21. The apparatus of claim 20, wherein the apparatus is configured such that a top surface of the substrate support is positioned above a bottom surface of the cylindrical wall during processing of a substrate in the apparatus. 